Fuel Injector Correction via Pressure Drop Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for fuel metering in internal combustion engines are inadequate in accurately monitoring and correcting individual fuel injector deviations, leading to inconsistencies in fuel delivery and emissions compliance.
Innovation Solution
A method that calculates a correction value for fuel metering by determining the static flow rate through fuel injectors using the ratio of pressure differences and durations in the high-pressure accumulator, allowing for precise adjustment of injection durations and minimizing needle dynamics and static flow rate errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If global correction methods (lambda control or mixture adaptation) are used to correct static flow rate errors, then all fuel injectors are corrected jointly, but individual fuel injector deviations cannot be detected or corrected
Solution Approach 1:
The patent segments the global correction approach into individual injector-level corrections. By measuring the pressure drop in the high-pressure accumulator specifically during each injector's operation, the system can identify and correct deviations for each individual fuel injector rather than applying a global correction to all injectors collectively.
Solution Approach 2:
The patent applies partial action by focusing measurement and correction efforts only on the specific injector being tested at each moment. The system performs measurements for individual injectors sequentially rather than attempting to measure all injectors simultaneously, enabling precise individual detection without requiring overly complex simultaneous multi-injector monitoring infrastructure.
2Reliability
If controlled valve operation is used to reduce needle dynamics influence, then opening duration can be regulated, but static flow rate errors from injection hole geometry and needle lift tolerances remain uncorrected
Solution Approach 1:
The patent implements feedback by measuring the actual pressure drop during injection and using this information to calculate and correct static flow rate deviations. The system continuously monitors the pressure difference in the high-pressure accumulator and uses this feedback to identify injectors with geometric or lift tolerances that cause flow rate errors, then applies corrective measures.
Solution Approach 2:
The patent changes the approach from controlling only valve operation parameters to also measuring and correcting static flow rate parameters. By introducing pressure drop measurements and using them to calculate correction factors, the system addresses static flow rate errors that result from manufacturing tolerances in injection hole geometry and needle lift, complementing the controlled valve operation approach.
3Quantity of substance
If pressure drop monitoring in the high pressure accumulator is used to monitor fuel quantity, then delivery quantity can be monitored, but detailed ascertainment of causes and correction is not possible
Solution Approach 1:
The patent applies preliminary action by isolating and testing individual injectors before performing detailed analysis. The system sequentially activates each injector while monitoring pressure drop, allowing it to attribute pressure changes to specific injectors. This preliminary identification of which injector is deviating enables subsequent detailed analysis of the cause (geometric tolerance vs. lift tolerance) and targeted correction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables precise correction of fuel metering for each injector, improving engine efficiency and emissions compliance by accounting for injector-specific deviations and reducing systematic errors, thereby optimizing fuel delivery and exhaust gas quality.
Implementation Method 1
fuel is injected from a high pressure accumulator into a combustion chamber
Implementation Method 2
the fuel quantity, or its volume, delivered by a fuel injector during an injection process is proportional or at least sufficiently proportional to the associated pressure difference
Data Source
AI summary
A method for ascertaining a correction value for a fuel metering of a fuel injector of an internal combustion engine, in which fuel is injected from a high pressure accumulator into a combustion chamber with the aid of the fuel injector, a value which is representative for a static flow rate through the fuel injector being ascertained by way of ascertaining, during at least one injection process of the fuel injector, a ratio of a pressure difference occurring in the high pressure accumulator as a result of the injection process and an associated duration which is characteristic for the injection process, and the correction value being ascertained on the basis of a comparison of the representative value with a comparative value.